Abdominal Aortic Aneurysm Flashcards
def
abnormal localised dilatation of the abdominal aorta >3cm (or >50% over normal diameter)
where do AAA most commonly occur
infrarenal aorta (95%)
aetiology
collagen + elastin degeneration in the arterial wall associated with 1 atherosclerosis 2 arteritis 3 CTD (marfans, ehlers-danlos)
associations/risk factors
1 smoking 2 family history (10x risk if first-degree relative affected) 3 HTN 4 CAD 5 popliteal artery aneurysms
what is the risk of rupture of a AAA related to
diameter
what is the risk of rupture of a 5-5.9cm AAA
3.3%PA
what is the risk of rupture of a 6-6.9cm AAA
9.4%PA
what is the risk of rupture of a 7-7.9cm AAA
24%PA
epi
increases with age
males>females
history
commonly asymptomatic symptomatic -rupture of undiagnosed AAA 1 epigastric/back pain 2 collapse
DDx for rupture of AAA
1 renal colic
2 musculoskeletal
3 diverticulitis
why might an intact AAA cause back pain
due to vertebral erosion
why might an intact AAA cause lower limb ischaemia
distal embolisation
examination of AAA
expansile mass above the umbilicus
examination of ruptured AAA
1 abdominal/back tenderness
2 pallor
3 tachycardia
4 hypotension + hypovolaemic shock